Drill wash device with pre-mounted exchange insert

ABSTRACT

The present invention relates to a drill wash device ( 100 ), the drill wash device comprising a stationary washpipe ( 102 ), a rotating washpipe ( 103 ), a pre-mounted, replaceable exchange insert ( 1 ) for connecting the stationary washpipe ( 102 ) to the rotating washpipe ( 103 ), the exchange insert ( 1 ) comprising a mechanical seal assembly with a stationary seal ring ( 20 ) and a rotating seal ring ( 21 ), and a first adapter ( 108 ) which is arranged between the stationary washpipe ( 102 ) and the exchange insert ( 1 ), wherein the first adapter ( 108 ) comprises a first adjusting mechanism ( 116 ) operative in axial direction for changing an axial length of the first adapter ( 108 ), and wherein the exchange insert ( 1 ) comprises a second adjusting mechanism ( 6 ) operative in axial direction for changing an axial length of the exchange insert ( 1 ).

The present invention relates to a drill wash device with a pre-mountedexchange insert for connecting a stationary, non-rotating washpipe to arotating washpipe which is inserted into a drill hole.

For drillings in the earth's crust, particularly for raw materials,so-called washpipe assemblies are used, in which a drill head isarranged at the end of a rotating pipe. A washing or flushing liquid isguided through the pipe from above downwards into the drill hole, theliquid then exiting at the drill head and being returned along the outercircumference of the rotating pipe to the earth's surface. A problematicissue in such drill hole arrangements is a sealing between a stationarywashpipe and the rotating washpipe. To prevent any leaks at this sealingbetween stationary and rotating washpipe particularly underenvironmental aspects, conservative solutions are used as much aspossible. A sealing solution is e.g. a series connection of a pluralityof stationary seals, for instance stuffing-box seals or lip seals. Incase of failure of one of said stationary seals the subsequentstationary seal will then ensure the sealing function. Due to the greatloads arising during drilling the service life of the individualstationary seals is however very short. It is thus necessary to replacethe stationary seals after a short period of time. This, however, leadsto a standstill of the drilling rig and thus to considerable costs.Since the stationary seals have to be put individually over the pipeparts, the exchange efforts are also very great. Furthermore, EP 1 630347 B1 discloses a sealing between a rotating and a stationary pipewhich uses a mechanical seal. In principle, mechanical seals have theadvantage of a longer service life as long as damage to the slidingsurfaces can be avoided. To keep the sliding surfaces of said mechanicalseal always in contact with one another, if possible, a spring elementis provided that during operation applies a constant preload in axialdirection to the seal rings. Due to the great loads arising duringdrilling the mechanical seal must however also be replaced after sometime. To this end a nut-screw assembly is then provided for compressingthe spring elements in axial direction so as to terminate the preload onthe seal rings. It is only then that an exchange of the seal rings ispossible. This exchange process is complicated and time-consuming.Furthermore, the seal rings are removed or mounted again individually,so that there is the risk of damage to the sliding surfaces duringmounting. Here, particular attention must be paid that the sealingbetween rotating and stationary washpipe is arranged in a bell of adrilling tower at a height of several meters and that particularlyexternal influences, such as weather and temperature, cannot have anegative impact on the exchange operation because drilling is performedespecially at more and more inhospitable places, e.g. on the high seasand in cold regions of the earth. That is why the exchange must becarried out with utmost care despite possibly very adverse externalcircumstances so as to avoid damage to the sliding surfaces. This alsoleads to a long and complicated exchange process.

Furthermore, U.S. Pat. No. 4,557,489 discloses a sealing with seal ringswhich is pressure-compensated. For this purpose bores are eitherprovided in the seal rings in radial direction, the bores ensuringpressure compensation relative to the outer circumference of the sealrings, or bores are provided in seal ring holders and lead to the outercircumference of the seal rings to provide pressure compensation. Incase of damage to the seal, the seal rings must be replaced separately.

It is therefore the object of the present invention to provide a drillwash device with a rotating and a stationary washpipe which while beingof a simple and inexpensive construction particularly permits a fastseal-ring exchange.

This object is achieved with a drill wash device comprising the featuresof claim 1. The sub-claims show preferred developments of the invention.

The drill wash device according to the invention has the advantage thata seal ring exchange can be performed very rapidly and easily. Accordingto the invention a pre-mounted, replaceable exchange insert is providedfor connecting a stationary washpipe to a rotating washpipe, thepre-mounted exchange insert comprising a mechanical seal assembly with astationary seal ring and a rotating seal ring. A first adapter isprovided which is arranged between the stationary washpipe and thepre-mounted exchange insert. The first adapter is fixed to thestationary washpipe and comprises a first adjusting mechanism operativein axial direction. The pre-mounted exchange insert itself comprises asecond adjusting mechanism operative in axial direction for changing anaxial length of the exchange insert. Hence, two separate adjustingmechanisms are provided according to the invention, with one of the twoadjusting mechanisms being arranged on the stationary washpipe and theother one of the two adjusting mechanisms being integrated into thepre-mounted exchange insert. It is thereby possible to first extend thefirst adjusting mechanism on the first adapter after insertion of thepre-mounted exchange insert into a region between the stationary and therotating washpipe, so that the exchange insert is firmly fixed to thefirst adapter, and then to activate the second adjusting mechanism, sothat the pre-mounted exchange insert is connected to the rotatingwashpipe. Hence, although two adjusting mechanisms have to be providedaccording to the invention, these can be operated rapidly and easily oneafter the other, so that a fast exchange of the pre-mounted exchangeinsert is possible. Moreover, since mechanical seals are used in thepre-mounted exchange insert, a very long service life of the exchangeinsert can be achieved in comparison with series-connected stuffingboxes. Moreover, the pre-mounted exchange insert can be pre-mounted in aworkshop, or the like, so that all secondary sealing elements andpossibly existing spring elements can also be replaced. This also leadsto a longer service life of the exchange insert.

Preferably, the first adjusting mechanism comprises a first screwconnection with an outer ring and an inner ring between which a threadis formed. The axial length between the first adapter and thepre-mounted exchange insert can thereby be adapted by relative rotationof the outer ring with respect to the inner ring of the first adapter.

The outer ring of the first screw connection preferably comprises firsttool recesses on an outer circumferential surface which is configured toreceive a tool for rotating the outer ring relative to the inner ring.The recesses are preferably bores.

Further preferably, the second adjusting mechanism comprises a secondscrew connection with an external sleeve with an internal thread, and aninternal sleeve with an external thread. Hence, a threaded connectionwhich can be extended by relative rotation between external sleeve andinternal sleeve in axial direction is here also provided between theexternal sleeve and the internal sleeve. The pitches of the first andsecond screw connection are here preferably identical, but may also bedifferent.

Further preferably, an axial length of the internal sleeve is greaterthan an axial length of the external sleeve. Hence, the internal sleevealways protrudes beyond the external sleeve by a predetermined length.

Further preferably, on a portion which is not covered by the externalsleeve the internal sleeve is provided on its outer circumference withsecond tool recesses for receiving a tool for rotating the internalsleeve relative to the external sleeve. The second tool recesses arealso preferably bores. Particularly preferably, the second tool recesseshave the same geometrical dimensions as the first tool recesses. As aconsequence, a mechanic can adjust both the first adjusting mechanism onthe first adapter and the second adjusting mechanism on the exchangeinsert with the same tool.

To enable a torque transmission from the rotating washpipe to theexchange insert, the exchange insert comprises a projection protrudingin axial direction of the washpipe, preferably at an end directedtowards the rotating washpipe.

Further preferably, the exchange insert further comprises an aligningring which aligns the protruding projection on the exchange insert fortorque transmission from the rotating washpipe in circumferentialdirection. A reliable mounting and form-fit connection between theprojection of the exchange insert and the rotating washpipe can therebybe achieved.

According to a further preferred configuration of the present inventionthe drill wash device further comprises a second adapter between therotating washpipe and the exchange insert. Especially the mounting onthe rotating washpipe can thereby be simplified significantly.

To even further simplify a mounting operation, a mounting aid ispreferably provided which is arranged on the stationary washpipe. Themounting aid supports assembly and disassembly of the pre-mountedexchange insert in the area between the stationary and the rotatingwashpipe.

The mounting aid preferably comprises a first and a second guide armwhich are arranged on the first adapter. The two guide arms are providedpreferably in parallel with each other and further preferably comprisesupporting surfaces for supporting the pre-mounted exchange insert.Further preferably, the pre-mounted exchange insert comprises acircumferential groove for a form-fit engagement with the guide arms.

Further preferably, the second adjusting mechanism of the exchangeinsert comprises an anti-rotation device. The anti-rotation device ispreferably a threaded bolt, or the like. The anti-rotation devicethereby ensures that a relative position between the external sleeve andthe internal sleeve is reliably held during operation. In other words,after adjustment of the axial length of the exchange insert, which iscarried out by rotation between external sleeve and internal sleeve, theposition is secured by the anti-rotation device. Prior to disassemblythe anti-rotation device must of course be released, so that a rotationbetween external sleeve and internal sleeve is possible again to permita shortening of the axial length of the exchange insert.

The anti-rotation device is particularly preferably a threaded bolt witha spring-biased locking element, particularly a spring-biased ball,which is arranged on the tip of the threaded bolt. At a start positionin which the exchange insert is not axially extended yet, the lockingelement engages into a first recess on the external sleeve. This definesa basic position of the pre-mounted exchange insert. During preassemblya mechanic can thus easily discern when the pre-mounted position hasbeen reached. Furthermore, a second recess is provided on the externalsleeve, in which the locking element locks in place when the exchangeinsert has reached the axially extended end state, i.e. the end assemblystate, during assembly. Hence, there is also an indicator indicating acorrect position for the achievement of the end position of the exchangeinsert in the mounted state. These measures considerably facilitate theassembly which, as has been mentioned, must be carried out partly underextremely difficult conditions because of external influences. Due tothe spring-biased locking element, the locking in place during assemblyand the locking out of place during disassembly take place automaticallyowing to the rotating operation between external sleeve and internalsleeve of the screw connection.

The anti-rotation device is preferably arranged on an arm connected tothe internal sleeve, the external sleeve being arranged between the armand the internal sleeve.

Further preferably, the rotating and the stationary seal ring are eachprovided with a bandage. The seal rings can thereby withstand highpressure loads.

To avoid damage to the pre-mounted exchange insert during assembly orduring transportation of the exchange insert, the exchange insertpreferably comprises a transportation lock. The transportation lockcomprises at least one spring element to exert a bias or preload on themechanical seal assembly prior to a final assembly of the exchangeinsert. The preload is here exerted on the seal rings such that thesliding surfaces of the seal rings reliably abut on one another so as toavoid damage to the sliding surfaces. The transportation lock is herearranged between a connection component to the stationary washpipe and afirst seal ring carrier for holding the stationary seal ring. Thetransportation lock is further configured such that in the end-mountedstate of the exchange insert no preload is exerted on the mechanicalseal during operation. This is e.g. achieved by providing springelements which no longer exert a preload in the mounted state of theexchange insert, in which an axial length of the exchange insert hasbeen increased by the second adjusting mechanism. The spring elementscan e.g. have a correspondingly short length so that in the end-mounted,axially extended state of the exchange insert no preload is exerted onthe seal rings. Thanks to the dead weight of the seal ring and theweight of the first seal ring carrier the stationary seal ringnevertheless reliably lies on the rotating seal ring.

To avoid a situation where the pressure on the seal rings duringoperation gets excessively strong, the rotating and the stationary sealring are preferably provided with a respective bevel on the innercircumference. The bevel extends preferably from an inner circumferenceof the seal rings up to half a seal ring width. Particularly preferably,the bevels are equally provided on both seal rings.

A preferred embodiment of the invention shall be described hereinafterin detail with reference to the accompanying drawing, in which:

FIG. 1 is a schematic illustration of a drill wash device according tothe invention with a pre-mounted exchange insert,

FIG. 2 is a schematic, perspective illustration of an exchange operationof the exchange insert,

FIG. 3 is a schematic partial sectional view of the exchange insertduring a first mounting step in which the exchange insert is slid intothe drill wash device;

FIG. 4 is a schematic partial sectional view of the exchange insert inwhich the exchange insert is connected to a stationary washpipe,

FIG. 5 is a schematic partial sectional view of the exchange insertwhile being connected to a rotating washpipe,

FIG. 6 is a schematic perspective view of an adjusting ring for aligningthe exchange insert with respect to the rotating washpipe,

FIG. 7 is a schematic partial sectional view of the exchange insert inthe mounted state, and

FIG. 8 is a schematic sectional view of the exchange insert in themounted state, the stationary and the rotating washpipe being not shownfor the sake of clarity.

A drill wash device 100 according to a preferred embodiment of theinvention will now be described in detail with reference to FIGS. 1 to8.

As can be seen in FIG. 1, a pre-mounted exchange insert 1 is used in thedrill wash device 100. The drill wash device 100 comprises a drillingtower 101 and is configured to introduce a flushing or washing mediumfrom above into a drill hole 106 (arrow A). The drill wash device 100comprises a stationary washpipe 102 and a rotating washpipe 103 having afree end on which a drill head 104 is arranged. A washing medium isintroduced by means of a pump 105 via the stationary washpipe 102 intothe rotating washpipe 103 and exits on the drill head 104. The washingmedium then flows on the outer circumference of the rotating washpipe103 back to the surface into a separating device 107. In the separatingdevice 107, rocks, or the like, that have been washed out of the drillhole 106 are separated from the washing medium which can then berecirculated.

According to the invention a drill wash device 100 with pre-mountedexchange insert 1 is provided, which can be exchanged completely. Thisis schematically indicated in FIG. 2 by the double-headed arrow B. Thepre-mounted exchange insert is here mounted in a space 112 between thestationary washpipe 102 and the rotating washpipe 103. A first adapter108 is provided at the free end of the stationary washpipe 102, and asecond adapter 109 is provided at the opposite free end of the rotatingwashpipe 103. Furthermore, the first adapter 108 has formed thereonfirst and second guide arms 110, 111 which allow an easy insertion ofthe pre-mounted exchange insert 1. To this end two guide elements 10, 11are provided on the exchange insert 1 on a connection component 5. Theguide elements 10, 11 are here lying with their bottom side on therail-like guide arms 110, 111, so that the weight of the exchange insert1 after the latter has been slid onto the guide arms 110, 111 is carriedby said arms, and the mounting operation is facilitated. The connectioncomponent 5 further comprises a circumferential groove 50 for engagementwith the guide arms 110, 111.

As is particularly apparent from FIGS. 3 and 8, the pre-mounted exchangeinsert 1 according to the invention comprises a mechanical seal assembly2 with a stationary seal ring 20 and a rotating seal ring 26. A sealinggap 26 is formed between the two seal rings. The stationary seal ring 20is enclosed by a first bandage 22 and the rotating seal ring 21 isenclosed by a second bandage 23.

Furthermore, a first bevel 24 is provided on the stationary seal ring 20on the inner circumferential side thereof, and a second bevel 25 isprovided on the rotating seal ring 21 in mirror-inverted fashion withrespect to the sealing gap. The two bevels 24, 25 extend in radialdirection of the exchange insert.

The first adapter 108 of the drill wash device 100 comprises a firstadjusting mechanism 116 which is operative in axial direction. The firstadjusting mechanism 116 comprises a first screw connection 117 with anouter ring 118 and an inner ring 128 between which a thread 129 isprovided. Hence, an axial length of the first adapter 108 can beincreased or decreased by way of a relative rotation between the outerring 118 and the inner ring 119.

The exchange insert 1 further comprises a first seal ring carrier 3which holds the stationary seal ring 20, and a second seal ring carrier4 which holds the rotating seal ring 21. The first seal ring carrier 3is configured in two parts, consisting of a first carrier part 31 and asecond carrier part 32. Furthermore, a shoulder 33 is provided on theinner circumference of the first seal ring carrier 3.

The second seal ring carrier 4 is also configured in two partscomprising a first carrier part 41 and a second carrier part, which isan adjusting ring 42, and further comprises a plurality of projections43 extending in axial direction X-X of the exchange insert 1. Theprojections 43 serve to transmit a torque from the driven rotatingwashpipe 103 via the second adapter 109 and the second seal ring carrier4 to the rotating seal ring 21.

Furthermore, the pre-mounted exchange insert 1 comprises a secondadjusting mechanism 6 with a second screw connection 60. The secondadjusting mechanism 6 comprises an external sleeve 61 with an internalthread 63 and an internal sleeve 62 with an external thread 64. Theinternal thread 63 and the external thread 64 engage one another andupon a relative rotation between the external sleeve 61 and the internalsleeve 62 the pre-mounted exchange insert is elongated in axialdirection X-X of the second adjusting mechanism 6. FIG. 2 shows a startlength L1 of the pre-mounted exchange insert 1 in axial direction. FIG.8 shows the fully extended axial length L2 which is longer by a lengthL3 than the start length L1.

The internal sleeve 62 covers the mechanical seal 2 in radial directionand it provides a guide surface 66 for the rotating seal ring 21 on aradial outside of the bandage 23. Furthermore, the internal sleeve 62also holds the second seal ring carrier 4 via the adjusting ring 42 ofthe second seal ring carrier 4.

Furthermore, the exchange insert 1 according to the invention comprisesa plurality of spring elements 7 which are arranged between theconnection component 5 for a connection to the stationary washpipe 102and the first seal ring carrier 3. Each spring element 7 is arrangedaround a pin 70 for guiding and positioning the spring elements. Thespring elements 7 are arranged in pockets 51 in the connection component5.

The spring elements 7 ensure that in the state in which the exchangeinsert is not end-mounted (FIGS. 2, 3 and 4) a force F is exerted viathe first seal ring carrier 3 on the stationary seal ring 20, so thatthe stationary seal ring 20 reliably abuts on the rotating seal ring 21and the sliding surfaces touch each other (cf. FIG. 4). In theend-mounted state which is shown in FIGS. 7 and 8, the spring elements 7do however not exert any spring force on the mechanical seal 2. This ise.g. achieved by way of a corresponding design of a length of thesprings 7, so that in the end-mounted state of the exchange insert 1 inthe drill wash device 100 a spring distance 71 exists between an end ofthe spring elements 7 and the connection component 5, as shown in FIG.8.

Hence, the spring elements 7 form a transportation lock which prior to afinal end mounting of the exchange insert 1 exerts a constant preload inaxial direction X-X on the mechanical seal.

Furthermore, a sealing element 8 is arranged between the connectioncomponent 5 and the first seal ring carrier 3. Furthermore, the exchangeinsert 1 comprises a first, second, third and fourth secondary sealingelement 12, 13, 14, 15. The first secondary sealing element 12 sealsbetween the connection component 5 and the stationary washpipe 102, thesecond secondary sealing element 13 seals between the first seal ringcarrier 3 and the stationary seal ring 20, the third secondary sealingelement 14 seals between the rotating seal ring 20 and the second sealring carrier 4, and the fourth secondary sealing element 15 sealsbetween the second seal ring carrier 4 and the second adapter 109relative to the rotating washpipe 103.

The adjusting ring 42 of the second seal ring carrier which is rotatablefrom outside of the pre-mounted exchange insert 1 by means of a tool onopenings 9 permits an alignment of the second seal ring carrier 4 incircumferential direction. This is necessary for allowing a torquetransmission via the projections 53, which are protruding in axialdirection X-X, from the second adapter 109 via the second seal ringcarrier 4 to the rotating seal ring 21. This process can be seen inFIGS. 5 and 6.

The first and second tool recesses 119 and 65 as well as the openings 9on the adjusting ring preferably have an identical geometric shape, e.g.a bore, so that they are adjustable by means of the same tool.

The second adapter 109 comprises recesses 44 formed to conform to theprojections 43, so that a form-fit connection is possible between thesecond adapter 109 and the adjusting ring 42.

Furthermore, an anti-rotation device 16 is provided for fixing arelative position of the second adjusting mechanism 6 between theexternal sleeve 61 and the internal sleeve 62. The anti-rotation device16 of this embodiment is a threaded bolt which fixes a relative positionbetween the external sleeve 61 and the internal sleeve 62. The threadedbolt comprises a spring-biased ball which in the not yet end-mountedposition locks into a first recess 67 on the outer circumference of theexternal sleeve 61 (FIG. 3). The anti-rotation device is here arrangedon an arm 69 which is connected to the internal sleeve, so that theexternal sleeve 61 is arranged between the arm 69 and the internalsleeve (cf. FIGS. 3 and 4). In the fully end-mounted position (FIG. 7),the ball is locked into a second recess 68 on the external sleeve 61,which serves as an indicator which indicates that the end position ofthe axially elongated exchange insert is reached. The two recesses 67,68 are arranged by about a quarter turn between internal sleeve andexternal sleeve on the circumference of the external sleeve 61. Bylocking the ball into the recesses 67, 68, a mechanic has—during therespective pre-mounting of the exchange insert—an indicator indicatingthe correct position of the components internal sleeve and externalsleeve relative to each other and also in the end-mounted position bylocking into the second recess 68. This permits a reliable mounting alsounder the most severe environmental conditions.

Since the exchange insert is pre-mounted according to the invention, theexchange insert can be fully pre-mounted without any problems in aworkshop. All secondary sealing elements 12, 13, 14, 15 can here also beexchanged in a simple way. The transportation lock by means of thespring elements 7 ensures that during transportation and installationshortly before an end installation position is reached a preload isalways exerted on the seal rings 20, 21, so that the sliding surfaces ofthe seal rings closely abut on one another, and damage to the slidingsurfaces can be avoided. According to the invention a complete exchangeof the exchange insert with mechanical seal assembly can thereby beprovided in a simple and fast way. Hence, during each exchange of theexchange insert new secondary sealing elements can be used, resulting inreduced maintenance and a respectively longer useful life of theexchange insert. In the case of a new exchange insert each of the springelements 7 can also be replaced, if necessary. Since the spring elements7 are arranged in the pockets 51, they are very well protected from thepumped medium, so that an exchange of the spring elements 7 is often notrequired.

The exchange operation will now be described in detail. After theexchange insert to be exchanged has been removed from the drill washdevice 100, a new pre-mounted exchange insert 1 is inserted into thedrill wash device 100, as outlined in FIG. 2. The new pre-mountedexchange insert 1 is pushed on the circumferential groove 50 and theguide elements 10, 11 onto the two guide arms 110, 111, so that after ashort push path the complete weight of the exchange insert 1 is carriedby the guide arms 110, 111. This considerably facilitates an assembly ofthe exchange insert which is normally carried out at a certain height inthe drilling tower 101 and must also be executed under very extremeweather conditions. Now, a mechanic must just push the pre-mountedexchange insert 1 along the guide arms 110, 111 into the assemblyposition. This inserted position is illustrated in FIG. 3. A firstdistance 80 is arranged between a face of the connection component 5 anda face of the first adapter 108, which is arranged on the stationarywashpipe 102 (cf. FIG. 3).

In a next step, this first distance 80 is eliminated in that a length ofthe first adapter 108 is changed in axial direction X-X of the exchangeinsert by means of the first adjusting mechanism 116 (FIG. 3). Here, thefirst adapter 108 comprises an outer ring 118 and an inner ring 128between which a thread 129 exists, so that the inner ring 128 gets intocontact with the connection component 5 by rotating at least one of therings. This position is shown in FIG. 4. In this embodiment, the outerring 118 comprises first tool recesses 119 in the form of cylindricalbores to permit a relative rotation between the outer ring 118 and theinner ring 128. A connection is thereby established between thepre-mounted exchange insert 1 and the stationary washpipe 102 via thefirst adapter 108. Since the connection is static, the first secondarysealing element 12 is adequate for sealing. The axial length L1 of thepre-mounted exchange insert has not been changed yet.

In a next step a connection is now established between the pre-mountedexchange insert 1 and the rotating washpipe 103. To this end the secondadjusting mechanism 6 is operated in that the internal sleeve 62 isrotated relative to the external sleeve 61. The internal sleeve 62 alsocomprises a portion which is exposed to the outside and in which pluralsecond tool recesses 65 are provided for the attachment of a tool. Theinternal sleeve 62 is here rotated relative to the external sleeve 61until the position shown in FIG. 5 is reached. In this position a finalconnection has not been established yet between the pre-mounted exchangeinsert 1 and the second adapter 109 on the rotating washpipe 103, but analignment of the torque transmitting mechanism must still be carried outbetween the second adapter 109 and the second seal ring carrier 4. Tothis end the adjusting ring 42 is rotated in circumferential direction,which is also made possible by way of a tool which can be attached fromthe outside to the adjusting ring 42. The alignment is of such a typethat the projections 43 of the second seal ring carrier 4 are arrangedover the corresponding recesses 44 of the second adapter 109, as shownin FIG. 6.

After the alignment has been made, the internal sleeve 62 of theadjusting mechanism 6 is further rotated relative to the external sleeve61, so that a further elongation of the exchange insert 1 is carried outin axial direction X-X until the connecting end position, which is shownin FIGS. 7 and 8, is reached (axial length L2).

FIG. 8 also shows the pre-mounted exchange insert in the connecting endposition without showing the first and second adapter 108, 109 of thestationary and rotating washpipe for reasons of clarity.

Owing to the axial elongation of the exchange insert 1 the springelements 7 can relax completely, so that the spring distance 71 plottedin FIG. 8 exists between the free end of the spring element 7 and theconnection component 5. During operation the pressure on the seal ringsis then built up via the shoulder 33. The spring elements may also bedesigned such that there is no spring distance from the connectioncomponent 5, but that a spring force is no longer exerted betweenconnection component 5 and first seal ring carrier 4.

The spring elements 7 are here arranged in correspondingly formedpockets 51 in the connection component 5.

As a last step, the anti-rotation device 16 is then activated for fixinga relative position between the external sleeve 61 and the internalsleeve 62 of the adjusting mechanism 6. Here, the ball of theanti-rotation device locks in place in the second recess 68. Hence, themechanic possesses an indicator which indicates that the exchange inserthas been extended to the correct axial length L2. Subsequently, thedrill wash device 100 is again ready for use.

During operation a pressure is then exerted via the shoulder 33 at thefirst seal ring carrier 3 on the seal rings, so that a reliable sealingis possible at the sealing gap 26. In the end-mounted position, theexchange insert 1 thereby has an axial length which is extended bylength L3, starting from the axial length L1 (FIG. 2) to the axiallength L2 (FIG. 8).

Owing to the inventive idea of providing a drill wash device 100 with afirst and second adjusting mechanism 116, 6, which respectively permitan elongation in axial direction, it is possible to provide a fast andreliable exchange of a mechanical seal. The mechanical seal is hereintegrated into a pre-mounted replaceable exchange insert 1. Uponexchange of the mechanical seals the complete exchange insert 1 isreplaced. This can prevent the risk of damage to the seal rings 20, 21in case of replacement. When the first and second adjusting mechanismscomprise a respective screw connection, a particularly fast and simpleexchange is made possible by way of a relative rotation between the twocomponents forming the screw connection. The relative rotation is herecarried out by means of the same tool. A handling with individual sealrings at the drilling tower is not required. The pitches of the twoscrew connections of the adjusting mechanisms are here particularlypreferably provided in the same way. Furthermore, it should be notedthat the tool receiving means on the adjusting ring 42 is alsoconfigured in the same way as on the first and second adjustingmechanism. Thus, only one single tool is needed for the completeassembly of the replaceable exchange insert 1. The exchange can here becarried out by only one mechanic.

LIST OF REFERENCE NUMERALS

-   1 exchange insert-   2 mechanical seal assembly-   3 first seal ring carrier-   4 second seal ring carrier-   5 connection component-   6 second adjusting mechanism-   7 spring element-   8 sealing element-   9 opening-   10, 11 guide elements-   12-15 secondary sealing elements-   16 anti-rotation device-   17 preloaded locking element-   20 stationary seal ring-   21 rotating seal ring-   22 first bandage-   23 second bandage-   24 first bevel-   25 second bevel-   26 sealing gap-   31 first carrier part-   32 second carrier part-   33 shoulder-   41 first carrier part-   42 adjusting ring-   43 projection-   44 recess-   50 circumferential groove-   51 pocket-   60 second screw connection-   61 external sleeve-   62 internal sleeve-   63 internal thread-   64 external thread-   65 second tool recess-   66 guide surface-   67 first recess-   68 second recess-   69 arm-   70 pin for positioning-   71 spring distance-   80 first distance-   100 drill wash device-   101 drilling tower-   102 stationary washpipe-   103 rotating washpipe-   104 drill head-   105 pump-   106 drill hole-   107 separating device-   108 first adapter-   109 second adapter-   110 first guide arm-   111 second guide arm-   112 space-   116 first adjusting mechanism-   117 first screw connection-   118 outer ring-   119 first tool recess-   128 inner ring-   129 thread

AM 55291323.1

1. A drill wash device, comprising: a stationary washpipe; a rotatingwashpipe; a pre-mounted, replaceable exchange insert for connecting thestationary washpipe to the rotating washpipe, the exchange insertcomprising a mechanical seal assembly with a stationary seal ring and arotating seal ring, and a first adapter which is arranged between thestationary washpipe and the exchange insert, wherein the first adaptercomprises a first adjusting mechanism operative in axial direction forchanging an axial length of the first adapter; and wherein the exchangeinsert comprises a second adjusting mechanism operative in axialdirection for changing an axial length of the exchange insert.
 2. Thedrill wash device according to claim 1, wherein the first adjustingmechanism comprises a first screw connection with an outer ring with aninternal thread, and an inner ring with an external thread.
 3. The drillwash device according to claim 2, wherein the outer ring of the firstscrew connection comprises first tool recesses on an outercircumferential surface which are configured to receive a tool forrotating the outer ring relative to the inner ring.
 4. The drill washdevice according to claim 1, wherein the second adjusting mechanismcomprises a second screw connection with an external sleeve with aninternal thread and an internal sleeve with an external thread.
 5. Thedrill wash device according to claim 4, wherein an axial length of theinternal sleeve is greater than an axial length of the external sleeve.6. The drill wash device according to claim 4, wherein second toolrecesses are provided on the internal sleeve on a portion not covered bythe external sleeve, for receiving a tool for rotating the internalsleeve relative to the external sleeve.
 7. The drill wash deviceaccording to claim 3, wherein a geometric shape of the first toolrecesses and a geometric shape of the second tool recesses areidentical.
 8. The drill wash device according to claim 1, wherein at anend directed towards the rotating washpipe the pre-mounted exchangeinsert comprises a projection protruding in axial direction (X-X) fortorque transmission from the rotating washpipe to the exchange insert.9. The drill wash device according to claim 8, wherein the exchangeinsert further comprises an aligning ring for aligning the protrudingprojection in a circumferential direction.
 10. The drill wash deviceaccording to claim 1, further comprising a second adapter between therotating washpipe and the exchange insert.
 11. The drill wash deviceaccording to claim 1, further comprising a mounting aid which isarranged on the stationary washpipe to support assembly and disassemblyof the pre-mounted exchange insert.
 12. The drill wash device accordingto claim 11, wherein the mounting aid comprises a first guide arm and asecond guide arm which are arranged on the first adapter.
 13. The drillwash device according to claim 12, wherein the pre-mounted exchangeinsert comprises a circumferential groove for engagement with the firstand second guide arms.
 14. The drill wash device according to claim 1,wherein the second adjusting mechanism comprises an anti-rotation deviceto fix a relative position between the external sleeve and the internalsleeve.
 15. The drill wash device according to claim 14, wherein theanti-rotation device comprises a threaded bolt with a locking elementwhich is spring-loaded on a tip of the threaded bolt and which in apre-mounted position locks into a first recess on the external sleeveand in an end-mounted position locks into a second recess on theexternal sleeve.